110KSI GRADE HIGH STRENGTH CORROSION RESISTANT MARTENSITIC STAINLESS STEEL PIPE

摘要

PURPOSE: To produce steel pipes excellent in corrosion resistance and toughness suitable for high depth oil wells by specifying the composition and δ-ferrite phase ratios of martensitic stainless steel pipes. ;CONSTITUTION: In a martensitic stainless steel pipe whose composition is, by weight, 0.02-0.15% C, 14.0-16.0% Cr, 1.0% Si, 2.0% Mn, 0.5-5.0% Ni, 0.05-0.15% N, 0.02% P, 0.01% S, 0.4-1.5% Mo and 0.001-0.1% Al (provided that the relationship, Cr-12C+0.75 Ni+10N≥13.0, is met), or further one or two of 0.05-0.3% V, 0.01-0.2% Nb, or 0.2-3.0% Cu compounded, and the balance Fe, the δ-ferrite phase of its structure is made ≥15%. It shows excellent toughness and CO₂ corrosion resistance when used for a high depth oil well contg. wet CO₂, salt content and a trace of hydrogen sulfide.;COPYRIGHT: (C)1994,JPO